From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 20/37] perf stat: Fix segfault for event group in repeat mode Date: Mon, 22 Jul 2019 14:38:22 -0300 Message-ID: <20190722173839.22898-21-acme@kernel.org> References: <20190722173839.22898-1-acme@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190722173839.22898-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Jiri Olsa , Numfor Mbiziwo-Tiapo , Alexander Shishkin , Ian Rogers , Mark Drayton , Peter Zijlstra , Song Liu , Stephane Eranian , Arnaldo Carvalho de Melo List-Id: linux-perf-users.vger.kernel.org From: Jiri Olsa Numfor Mbiziwo-Tiapo reported segfault on stat of event group in repeat mode: # perf stat -e '{cycles,instructions}' -r 10 ls It's caused by memory corruption due to not cleaned evsel's id array and index, which needs to be rebuilt in every stat iteration. Currently the ids index grows, while the array (which is also not freed) has the same size. Fixing this by releasing id array and zeroing ids index in perf_evsel__close function. We also need to keep the evsel_list alive for stat record (which is disabled in repeat mode). Reported-by: Numfor Mbiziwo-Tiapo Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Ian Rogers Cc: Mark Drayton Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Cc: Stephane Eranian Link: http://lkml.kernel.org/r/20190715142121.GC6032@krava Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-stat.c | 9 ++++++++- tools/perf/util/evsel.c | 2 ++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index b55a534b4de0..352cf39d7c2f 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -607,7 +607,13 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) * group leaders. */ read_counters(&(struct timespec) { .tv_nsec = t1-t0 }); - perf_evlist__close(evsel_list); + + /* + * We need to keep evsel_list alive, because it's processed + * later the evsel_list will be closed after. + */ + if (!STAT_RECORD) + perf_evlist__close(evsel_list); return WEXITSTATUS(status); } @@ -1997,6 +2003,7 @@ int cmd_stat(int argc, const char **argv) perf_session__write_header(perf_stat.session, evsel_list, fd, true); } + perf_evlist__close(evsel_list); perf_session__delete(perf_stat.session); } diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index b787ec778049..7d1757a2ec46 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -1292,6 +1292,7 @@ static void perf_evsel__free_id(struct perf_evsel *evsel) xyarray__delete(evsel->sample_id); evsel->sample_id = NULL; zfree(&evsel->id); + evsel->ids = 0; } static void perf_evsel__free_config_terms(struct perf_evsel *evsel) @@ -2078,6 +2079,7 @@ void perf_evsel__close(struct perf_evsel *evsel) perf_evsel__close_fd(evsel); perf_evsel__free_fd(evsel); + perf_evsel__free_id(evsel); } int perf_evsel__open_per_cpu(struct perf_evsel *evsel, -- 2.21.0